Shelf



FIG. 1 is a perspective view showing my new design for a shelf.

FIG. 2 is a front view thereof; the rear view being a mirror image.

FIG. 3 is a right side view thereof; the left side view being a mirror image.

FIG. 4 is a top view thereof.

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a second perspective view thereof, shown in environmental use.

The broken lines represent unclaimed subject matter and form no part of the claimed design. 

CLAIM I claim the ornamental design for a shelf, as shown and described. 